Abstract Detail

Cure Modeling of Dormancy and Germination in Heterocarpic Grindelia Species.

Seed germination is a dynamic process resulting from a seed experiencing conditions that break or induce dormancy and conditions that promote or inhibit radicle elongation and activity of the shoot apical meristem. Heterocarpic species provide a unique system for studying dormancyand germination because plants use a bet-hedging strategy to produce and provision seeds with dissimilar dormancy and germination ecology. Studies have shown basic differences between heterocarpic fruits and seeds within them, but there have been no detailed studies of thermal parameters that influence dormancy and germination. We used the cure model to investigate minimum and maximum thermal thresholds at which germination can occur to evaluate depth of dormancy and the effects of stratification and after-ripening in two species of Grindelia. The results provide further insights on the spatial and temporal dynamics of this unique reproductive system and broader perspectives on the impact of climate change on seed bank ecology.